The present invention relates to a small size multi-way waterproof connector with an improved waterproof property between a connector housing and a plurality of electric wires connected with terminals, and a method of assembling the same.
A related waterproof connector, which is disclosed in Japanese Patent Publication No. 11-354200, will be explained with reference to FIGS. 6 to 8. A connector housing 11 of a waterproof connector 10' comprises a synthetic resin inner housing 12 having a plurality of terminal chambers 13 formed integrally therewith, a synthetic resin outer housing 17 for fitting the inner housing 12 to the inside thereof, and a synthetic resin spacer 28 disposed between the inner housing 12 and the outer housing 17 for holding female terminals 14 accommodated in each terminal chamber 13 of the inner housing 12.
As shown in FIGS. 6 and 7, the inner housing 12 has a box part 12a with the rear side of the upper and lower faces opened, for forming the terminal chambers 13 in a space formed with the center horizontal wall 12b and vertical side walls 12c, serving also as partition walls in the vertical direction. The female terminals 14 can be accommodated in each terminal chamber 13. Moreover, engagement claws 15 are formed integrally, projecting from both sides and the center of the upper and lower faces of the box part 12a as well as flange parts (not illustrated) are formed integrally projecting from the front end of the both side center parts. Rectangular insertion holes 12d for inserting male terminals of a mating connector (not illustrated) therethrough are formed in the front wall of the box part 12a at a position corresponding to each terminal chamber 13. Furthermore, a pair of press-connecting blades 14b are formed by bending in both side plate parts in the rear part of a box part 14a of the female terminals.
As shown in FIGS. 6 and 7, the outer housing 17 has a double box-like shape with the front side opened, with a substantially quadrilateral pipe-like inner wall part 17a, a substantially quadrilateral pipe-like outer wall part 17b for containing the inner wall part 17a, and a bottom wall part (wall part) 17c, connecting the rear parts of the inner and outer wall parts 17a, 17b. A thick portion is provided in the center of the bottom wall part 17c. Rubber plug chambers 19 having a large diameter round cross-section for accommodating waterproof rubber plugs 18 by press-in are formed at a position corresponding to each terminal chamber 13 at the front side with respect to the thick portion as well as electric wire insertion holes 21 having a small diameter round cross-section for inserting electric wires 20 therethrough are formed, communicating with each corresponding rubber plug chamber 19 at the rear side with respect to the thick portion.
Moreover, rectangular engagement holes 22 to be engaged with each engagement claw 15 at both sides of the upper and lower faces of the box part 12a of the inner housing 12 are formed at both front sides of the upper and lower walls of the inner wall part 17a of the outer housing 17 as well as rectangular longitudinal engagement holes 23 to be engaged with each engagement claw 15 at the center of the upper and lower faces of the box part 12a of the inner housing 12 are formed at the front center portion of the upper and lower walls of the inner wall part 17a. Furthermore, a V-shaped packing receiving part 25 for receiving an annular rubber waterproof packing 24 is formed integrally, projecting from the deep part of the outer face side of the inner wall part 17a of the outer housing 17.
Tapered faces 26 are formed in the front rim of the inner face side of the inner wall part 17a of the outer housing at a position corresponding to each engagement hole 22, 23. Moreover, engagement holes 27 to be engaged with flexible engaging arms of a mating connector (not illustrated) are formed at the front side of the upper and lower walls of the outer wall part 17b of the outer housing 17.
As shown in FIGS. 6 and 7, the spacer 28 forms a box-like shape with the front side opened, with a substantially quadrilateral pipe-like body 28. to be fitted with the inner face side of the inner wall part 17a of the outer housing 17, a substantially quadrilateral pipe-like brim part 28b formed integrally with the front end of the body 28a, bent rearward therefrom, to be fitted with the outer face side of the inner wall part 17a of the outer housing, and a bottom wall part 28c of the body 28a.
Accordingly, the box part 12a of the inner housing 12 can be fitted into the body 28a of the spacer 28. Rib-like projections 29 for preventing fall-off of the terminals are formed integrally, projecting from the inner face of the upper and lower walls of the body 28a of the spacer 28, to be engaged with the rear end rim of the box part 14a of the female terminals 14 accommodated in each terminal chamber 13.
Moreover, notch portions 30 are formed in the front side of the portion connecting the body 28a and the brim part 28b of the spacer 28 at a position corresponding to each engagement claw 15 of the inner housing 12. Engagement claws 32 to be engaged with each engagement hole 23 of the outer housing 17 are formed integrally, projecting form the outer face side of the upper and lower walls of the body 28a of the spacer 28 between the upper and lower side notch portions 30. Furthermore, the tip portion of the brim part 28b can hold the packing 24 engaged with the packing receiving part 25 of the inner wall part 17a of the outer housing 17 when the fitting operation with respect to the outer housing 17 is completed.
Moreover, electric wire insertion holes 33 are formed in the bottom wall part 28c of the spacer 28 at a position corresponding to each electric wire insertion hole 21 of the outer housing 17. Furthermore, the bottom wall part 28c of the spacer 28 can hold the rubber plugs 18 inserted in each rubber plug chamber 19 of the bottom wall part 17c of the outer housing when the fitting operation with respect to the outer housing 17 is completed. As shown in FIG. 6, each electric wire 20 inserted through each electric wire insertion hole 21 of the outer housing 17, each rubber plug 18 and each electric wire insertion hole 33 of the spacer 28 is press-connected between the pair of the press-connecting blades 14b of each female terminal accommodated in each terminal chamber 13 of the inner housing 12 so that each terminal chamber 13 and each electric wire 20 are sealed with the rubber plug 18 and the packing 24, respectively.
Reverse conical tapered faces 19a are formed at the entrance side of each rubber plug chamber 19 inside the bottom wall part 17c of the outer housing 17. Moreover, reverse conical tapered faces 28d, serving also as rubber plug pressing parts, are formed around each electric wire insertion hole 33 outside the bottom wall part 28c of the spacer 28. The rubber plugs 18 can be interposed between the reverse conical faces 19a of each rubber plug chamber 19 and the reverse conical faces 28d around each electric wire insertion hole 33 of the spacer 28 before accommodating the rubber plugs 18 in each rubber plug chamber 19 of the outer housing 17 (at the time of the temporary engagement with the front side of the body 28a of the spacer 28 in the inner wall part 17a of the outer housing 17 shown in FIG. 6).
Moreover, as shown in FIG. 8, conical tapered faces 18a are formed at both end sides of the rubber plugs 18 for inserting the electric wires 20 therethrough. The inner diameter Rb (that is, the diameter of the electric wire insertion holes 18b of the rubber plugs 18) of the rubber plugs 18 is set to be equal to or larger than the diameter R of the electric wires 20 (Rb.gtoreq.R). Furthermore, the outer diameter Ra of the rubber plugs 18 is formed to be larger than the diameter D of the rubber plug chambers 19 such that the sealing relationship (Ra-Rb+R&gt;D) can be provided in the rubber plug chambers 19.
The waterproof rubber plugs 18 have a substantially cylindrical shape with the rugged inner and outer circumferential faces so that the electric wires 20 can be inserted through the inside thereof without having a gap.
In assembling the waterproof connector 10' with the above-mentioned configuration, the packing 24 is inserted and set preliminarily in the packing receiving part 25 of the inner wall part 17a of the outer housing 17 comprising the outside of the connector housing 11. The electric wires 20 are inserted through the plurality of the electric wire insertion holes 21 of the bottom wall part 17c of the outer housing 17 from the outside thereof, and the electric wires 20 are inserted through each electric wire insertion hole 33 of the bottom wall part 28c of the spacer 28 from the outside thereof after inserting the electric wires 20 through the rubber plugs 18.
As shown in FIG. 6, the front side of the body 28a of the spacer 28 is fitted into the inner wall part 17a of the outer housing 17 for temporary engagement with the rubber plugs 18 interposed between the reverse conical face 19a of each rubber plug chamber 19 and the reverse conical face 28d of each electric wire insertion hole 33 of the bottom wall part 28c of the spacer 28 without being accommodated in each rubber plug chamber 19 inside the bottom wall part 17c of the outer housing 17. Then, each electric wire 20 is press-connected to the pair of the press-connecting blades 14b of each terminal 14 accommodated in the plurality of the terminal chambers 13 in the inner housing 12 comprising the inside of the connector housing 11.
Next, as shown in FIG. 7, if the inner housing 12 is fitted to the inside of the body 28a of the spacer 28 such that the body 28a of the spacer 28 is fitted completely in the inner wall part 17a of the outer housing for the full engagement while sliding each electric wire 20 with respect to each electric wire insertion hole 33, 21 of the bottom wall part 28c of the spacer 28 and the bottom wall part 17c of the outer housing 17, the assembly of the waterproof connector 10' with each electric wire 20 sealed by each rubber plug 18 can be completed by accommodating each rubber plug 18 in each rubber plug chamber 19 with pressure by the reverse conical face 28d around each electric wire insertion hole 33 of the bottom wall part 28c of the spacer 28. Accordingly, since pressure is not applied from the rubber plugs 18 at the time of fitting the inner housing 12 into the spacer 28 fitted to the inside of the outer housing 17 via the rubber plugs 18 in the temporarily engaged state, the waterproof connector 10' can be assembled smoothly without bending of the electric wires 20, and thus the assembly operativity as a whole can further be improved.
However, according to the related waterproof connector 10', the electric wires 20 are inserted through the rubber plugs 18 not accommodated in each rubber plug chamber 19 of the outer housing 17, and the electric wires 20 are press-connected to the female terminal 14 accommodated in the terminal chambers 13 of the inner housing 12 so that the rubber plugs 18 are accommodated with pressure each rubber plug chamber 19 of the outer housing 17 by fully engaging the inner housing 12 in the inside of the outer housing 17 via the spacer 28 while sliding and moving each electric wire 20 with the inner housing 12 in the electric wire insertion holes 18b of the rubber plugs 18. Therefore, since the rubber plugs 18 and the electric wires 20 are set while sliding, in the case the number of the rubber plugs 18 is large, the total sum of the sliding friction force between the rubber plugs 18 and the electric wires 20 becomes large so that the fitting load of the inner housing 12 and the outer housing 17 can be large so as to cause a trouble in the production of the wire harness. That is, in the case the number of the rubber plugs 18 is large, there is a risk of deteriorating the assembly operativity of the waterproof connector 10' due to the increased operation load (fitting load) by the sliding friction between the rubber plugs 18 and the electric wires 20 at the time of the housing fitting operation of fitting the inner housing 12 into the outer housing 17 side via the spacer 28.